#ifndef THREADS_INTERRUPT_H
#define THREADS_INTERRUPT_H

#include <stdbool.h>
#include <stdint.h>

/* Interrupts on or off? */
enum intr_level
{
    INTR_OFF,
    /* Interrupts disabled. */
    INTR_ON /* Interrupts enabled. */
};

enum intr_level intr_get_level(void);
enum intr_level intr_set_level(enum intr_level);
enum intr_level intr_enable(void);
enum intr_level intr_disable(void);

/* Interrupt stack frame. */
struct intr_frame
{
    /* Pushed by intr_entry in intr-stubs.S.
       These are the interrupted task's saved registers. */
    uint32_t edi;       /* Saved EDI. */
    uint32_t esi;       /* Saved ESI. */
    uint32_t ebp;       /* Saved EBP. */
    uint32_t esp_dummy; /* Not used. */
    uint32_t ebx;       /* Saved EBX. */
    uint32_t edx;       /* Saved EDX. */
    uint32_t ecx;       /* Saved ECX. */
    uint32_t eax;       /* Saved EAX. */
    uint16_t gs, : 16;  /* Saved GS segment register. */
    uint16_t fs, : 16;  /* Saved FS segment register. */
    uint16_t es, : 16;  /* Saved ES segment register. */
    uint16_t ds, : 16;  /* Saved DS segment register. */

    /* Pushed by intrNN_stub in intr-stubs.S. */
    uint32_t vec_no; /* Interrupt vector number. */

    /* Sometimes pushed by the CPU,
       otherwise for consistency pushed as 0 by intrNN_stub.
       The CPU puts it just under `eip', but we move it here. */
    uint32_t error_code; /* Error code. */

    /* Pushed by intrNN_stub in intr-stubs.S.
       This frame pointer eases interpretation of backtraces. */
    void *frame_pointer; /* Saved EBP (frame pointer). */

    /* Pushed by the CPU.
       These are the interrupted task's saved registers. */
    void (*eip)(void); /* Next instruction to execute. */
    uint16_t cs, : 16; /* Code segment for eip. */
    uint32_t eflags;   /* Saved CPU flags. */
    void *esp;         /* Saved stack pointer. */
    uint16_t ss, : 16; /* Data segment for esp. */
};

typedef void intr_handler_func(struct intr_frame *);

void intr_init(void);
void intr_register_ext(uint8_t vec, intr_handler_func *, const char *name);
void intr_register_int(uint8_t vec, int dpl, enum intr_level,
                       intr_handler_func *, const char *name);
bool intr_context(void);
void intr_yield_on_return(void);

void intr_dump_frame(const struct intr_frame *);
const char *intr_name(uint8_t vec);

#endif /* threads/interrupt.h */
